青藏高原东北部唐古特铁线莲种子萌发特性的研究   总被引：1，自引：0，他引：1  

拉本  刘玉萍  苏旭  吴学明 《种子》2012,31(6):76-78,82

唐古特铁线莲是中国一种珍贵药用植物,青海省是其主要分布区。针对唐古特铁线莲野生资源受到严重破坏的情况,对其人工引种栽培过程中种子发芽率进行了研究,旨在为唐古特铁线莲的栽培和野生资源的保护提供理论依据。研究表明:自然状态下唐古特铁线莲种子萌发率低;经变温、温汤浸种、KNO3和GA3处理后种子发芽率显著提高。  相似文献   

蒙古斑点马黑、白毛色区域皮肤中相关基因的表达研究     

白东义  拉希玛  赵若阳  陶娜拉  韩海格  丁文淇  贾紫洁  刘慧莹  王文兴  黄博光  芒来 《畜牧兽医学报》2022,53(1):100-111

本试验以蒙古斑点马为研究对象,分别对蒙古斑点马体躯白色区域和黑色区域皮肤的表型和差异表达基因进行分析并验证,试图解析蒙古斑点马毛色形成的分子机制,为今后保护和开发利用蒙古斑点马奠定基础.选择蒙古斑点马体躯白色和黑色区域皮肤制作组织切片,HE染色后在显微镜下观察其表型差异;对白色和黑色区域皮肤组织进行转录组测序,比较差异...  相似文献   

娟姗牛与西杂牛杂交后代生长发育观测          下载免费PDF全文

石红梅  包永清  马登录  王文飙  徐海  马桂琳  包扎西加措  杨江海  张彩霞  拉毛杰布  訾云南  郭淑珍 《中国牛业科学》2022,48(1):29-31

[目的]旨在繁育适于牦牛杂交改良的乳肉兼用父本.[方法]在海拔相对较低的半农半牧区,用娟姗牛与西杂牛杂交,观察杂交后代的生长发育和配种情况.[结果]娟姗牛与西杂牛的杂交后代在甘南州高海拔地区具有较好的适应性,表现出明显的杂交优势,能与甘南牦牛自然交配.  相似文献   

Risk factors for superficial digital flexor tendinopathy in Thoroughbred racehorses in steeplechase starts in the United Kingdom (2001–2009)     

R.J.M. Reardon  L.A. Boden  D.J. Mellor  S. Love  J.R. Newton  A.J. Stirk  T.D.H. Parkin 《Veterinary journal (London, England : 1997)》2013,195(3):325-330

The objective of this study was to identify risk factors for superficial digital flexor (SDF) tendinopathy in Thoroughbred horses in steeplechase races in the United Kingdom. Potential risk factors for SDF tendinopathy were studied between 1st January 2001 and 31st December 2009 using a cohort study design with 648 injuries sustained in 102,894 starts. Potential risk factors were screened using univariable logistic regression prior to multivariable model building.In the final multivariable model, 12 statistically significant risk factors were identified. Variables that increased the odds of SDF tendinopathy included firmer going, increased horse age, and racing in the summer compared to other seasons. Variables that decreased the odds included having a higher official rating and the number of starts in the preceding days.Fewer and different risk factors were identified than in an equivalent model of SDF tendinopathy in hurdle racing, highlighting potential differences between these disciplines. Further collection of training and racecourse information would be beneficial and may help to explain further some of the associations identified in this study. The results will facilitate the development of strategies to improve overall safety of horses in UK steeplechase racing.  相似文献   

Acquired proximal renal tubulopathy in dogs exposed to a common dried chicken treat: retrospective study of 108 cases (2007–2009)     

MF Thompson  LM Fleeman  AE Kessell  LA Steenhard  SF Foster 《Australian veterinary journal》2013,91(9):368-373

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Application and Commercialization of Flow Cytometrically Sex-Sorted Semen   总被引：1，自引：0，他引：1  

D Rath  LA Johnson 《Reproduction in domestic animals》2008,43(S2):338-346

The current technology to sort X and Y chromosome bearing sperm population requires individual identification and selection of spermatozoa in a modified high-speed flow cytometer. For farm animal species, the technology is capable of producing sexed sperm at greater than 90% purity. However, only in the bovine, the technology has reached a developmental level that allows its commercial application. Meanwhile, the demand for female calves has grown rapidly, which encourages the demand for sex-sorted semen from high genetic value bulls. The success of the technology will depend mainly on the fertilizing capacity of the sorted spermatozoa, as this is the most affecting and economically relevant factor. To date, fertility is still variable and is quite dependant on post-sort processing. New processing techniques are under investigation and will likely be able to improve the fertility rates after AI with sex-sorted semen. It is of great importance to select the right bulls and to test the sorted samples on a routine basis. In addition to the demand for sex-sorted semen by the cattle industry, there is also a significant demand expressed by pig farmers. However, it is still unknown if the use of sex-sorted semen through commercial pig AI will be economically feasible. For the pig, the combination of in vitro fertilization with sexed semen and non-surgical embryo transfer is an alternative that merits further scientific attention. Recent developments in ovine AI and ET will make it very likely that commercial sheep industry will adopt the sexing technology in their breeding concepts.  相似文献   

Climate and vegetation history of the midcontinent from 75 to 25 ka: A speleothem record from crevice cave, missouri, USA   总被引：3，自引：0，他引：3  

JA Dorale  RL Edwards  E Ito  LA Gonzalez 《Science (New York, N.Y.)》1998,282(5395):1871-1874

Four Missouri stalagmites yield consistent overlapping records of oxygen and carbon isotopic changes and provide a climate and vegetation history with submillennial resolution from 75 to 25 thousand years ago (ka). The thorium-230-dated records reveal that between 75 and 55 ka, the midcontinental climate oscillated on millennial time scales between cold and warm, and vegetation alternated among forest, savanna, and prairie. Temperatures were highest and prairie vegetation peaked between 59 and 55 ka. Climate cooled and forest replaced grassland at 55 ka, when global ice sheets began to build during the early part of Marine Oxygen Isotope Stage 3.  相似文献   

Hunting behavior of a marine mammal beneath the antarctic fast Ice   总被引：1，自引：0，他引：1  

RW Davis  LA Fuiman  TM Williams  SO Collier  WP Hagey  SB Kanatous  S Kohin  M Horning 《Science (New York, N.Y.)》1999,283(5404):993-996

The hunting behavior of a marine mammal was studied beneath the Antarctic fast ice with an animal-borne video system and data recorder. Weddell seals stalked large Antarctic cod and the smaller subice fish Pagothenia borchgrevinki, often with the under-ice surface for backlighting, which implies that vision is important for hunting. They approached to within centimeters of cod without startling the fish. Seals flushed P. borchgrevinki by blowing air into subice crevices or pursued them into the platelet ice. These observations highlight the broad range of insights that are possible with simultaneous recordings of video, audio, three-dimensional dive paths, and locomotor effort.  相似文献   

半夏SSR分子标记开发与遗传多样性     

张景  李晓东  宗庆波  何贝贝  拉基  景纳良  王柯月  钟淑梅  舒少华 《华中农业大学学报》2021,40(6):19-26

对半夏转录组数据进行分析,设计开发SSR引物,利用筛选出的SSR引物分析不同居群间半夏的遗传多样性,为半夏分子标记辅助育种提供支撑。结果显示:筛选出的19对多态性较高的引物在17个半夏居群中共检测到49个多态性位点,具有较高的多态性;利用UPGMA作图共将17个半夏居群分为3个类群;通过分子方差分析(AMOVA)发现半夏居群内的变异达到88%,说明群体与群体间的差异相对较小,遗传变异主要来源于个体间;居群间平均分化系数Fst为0.124,居群间基因流Nm值为1.765,表明居群间能正常地进行基因交流,且居群间遗传分化受基因流的影响较大。本研究利用SSR技术开发的19对SSR引物在不同半夏居群间具有一定的通用性、多态性,能将17份半夏材料明确区分。  相似文献   

Efficacy of thermal cautery for intermittent dorsal displacement of the soft palate as compared to conservatively treated horses: Results from 78 treadmill diagnosed horses     

S. Z. Barakzai  L. A. Boden  M. H. Hillyer  D. J. Marlin  P. M. Dixon 《Equine veterinary journal》2009,41(1):65-69

Reasons for performing study: Previously, objective comparisons of surgical procedures to relieve dorsal displacement of the soft palate (DDSP) have been limited by the presumptive basis of the diagnostic measures applied. Objectives: To assess and compare the efficacy of thermal cautery surgery to conservatively treated controls in racehorses definitively diagnosed with idiopathic intermittent DDSP. Hypothesis: Both conservative and surgical treatments have a beneficial result on racing performance in racehorses affected with DDSP. Methods: Race records were obtained for Thoroughbred racehorses definitively diagnosed with DDSP using highspeed treadmill endoscopy. Racing performance was assessed based on prize money won. Results: Forty‐eight horses that underwent thermal cautery and 30 conservatively treated controls were included. Pretreatment earnings significantly decreased in the race immediately prior to diagnosis. A high proportion of previously raced horses returned to racing after both treatments (90–96%). Intrahorse comparison of earnings in 3 races pre‐ vs. post treatment showed that 53% of conservatively treated horses and 36% of the thermal cautery group had improved performance. Although the difference between these 2 groups may be interpreted as being clinically significant, it was not statistically significant. Conclusions and potential relevance: A higher percentage of conservatively treated controls had improved individual performance compared to horses treated with thermal cautery. Thermal cautery appears less effective than other previously published surgical treatments for DDSP. Comparison of the 2 treatment methods should be interpreted cautiously because treatments were not randomised, resulting in baseline variability between groups.  相似文献